At least 31 people were reportedly killed in Pakistan as a result of a missile strike Wednesday by neighboring India, which is now preparing for retaliation.

Pakistan vowed to retaliate for the strike earlier in the day – the latest in the countries' deadly border dispute. 

The nuclear-armed neighbors have fought two previous wars over the region.

India fired missiles into Pakistani-administered Kashmir and Pakistani territory in several locations early Wednesday, according to CBS News. 

The death toll in Pakistan is being reported by officials in the country, who say the missile salvo is an act of war. 

India also claims there are casualties from Pakistani fire in the Indian-controlled portion of Kashmir, CBS also reports.

India said it struck infrastructure used by militants linked to last month's massacre of tourists in the Indian-administered portion of Kashmir, a disputed mountainous region, also according to CBS.